1. Field of the Invention
The present invention relates to a navigation system, and more particularly, to an apparatus and method for controlling a traffic information display in a navigation system, which is capable of displaying colors corresponding to traffic density of a travel route on a screen.
2. Description of the Related Art
In general, a navigation system displays a current location of a moving object on a map, which is displayed on a screen. The current location is calculated using information that is received from a global positioning system (hereinafter, referred to as a “GPS”).
Additionally, the navigation system provides a driver with a variety of information necessary for a travel route of the moving object, including a travel direction of the moving object, a distance to a desired destination, a current travel velocity of the moving object, a route previously set by a driver, an optimum route to the destination, and so forth. The term velocity is intended to encompass the scalar parameter speed as well as the vector parameter velocity.
The navigation system (or GPS) may be installed in various kinds of moving objects, such as vessels, airplanes and automobiles, and is widely used to check a current location and travel velocity of the moving object or to determine a travel route of the moving object. Specifically, the navigation system receives radio waves indicating latitude, longitude and altitude from a plurality of GPS satellites, performs a calculation operation, and visually and/or audibly informs the driver with map information including the current location of the moving object.
FIG. 1 is a construction of a related navigation system.
Referring to FIG. 1, a GPS receiver 102 receives predetermined location data through an antenna for the purpose of a navigation service. Here, the location data are transmitted from a plurality of GPS satellites 100. A velocity sensor/gyro sensor 104 constitutes a sensor part and senses a rotational angle and velocity of a moving object.
An input unit 106 is a user interface configured to receive various input key signals from a user and set a travel route.
A map data storage unit 108 stores map data and other additional information data. In general, the map data storage unit 108 is implemented with compact disk-read only memory (CD-ROM). ROM).
A control unit 110 controls an overall operation of the navigation system. The control unit 110 determines a current location of the moving object by using a reception signal of the GPS receiver 102 and matches the determined current location with the map data stored in the map data storage unit 108.
In case the user inputs an origin and a destination through the input unit 106, the control unit 110 searches to determine a travel route from the current location of the moving object to the destination by referring to the map data stored in the map data storage unit 108. The searched and determined travel route is displayed on a digital map of a display unit 114 through a display driving unit 112.
Additionally, the travel route of the moving object can be guided using a guidance voice that is outputted through a speaker 118 by a voice guidance unit 116.
The navigation system receives GPS satellite signals from the plurality of GPS satellites 100 located over the earth and checks the current location and the travel direction of the moving object to thereby track a travel trace. Additionally, the navigation system provides the driver with the shortest route among several travel routes from the origin to the destination.
Meanwhile, if information on a specific area is requested, the related navigation system provides traffic information on the specific area to a mobile telephone in a message form. The traffic information may be displayed in the form of text information on an electronic display board, which is a traffic information display unit installed on a road.
However, since such traffic information is provided in a form of text information, the amount of information is very large and mostly incorrect. Specifically, even if the moving object requests information on a road in a specific area, the requested information is not provided in a satisfactory form. Accordingly, the related navigation system has problems in that the traffic information has low reliability and it is impossible to actively cope with traffic conditions until the destination is reached.